Sheet inspecting and sorting apparatus



Dec. 24, 1968 W.J. HASELOW ETAL 3,417,939

I SHEET INSPECTING AND SORTING APPARATUS Filed Aug. 29, 1966 9 Sheets-Sheet 1 w. J. HASELOW ET AL 3,417,989

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SHEET INSPECTING AND SORTING APPARATUS 9 Sheets-Sheet a Filed Aug. 29, 1966 .wbw. nww QQ 8w WWW.-. @x v \\N N& V

wmww Dec. 24, 1968 9 Sheets-Sheet 6 Filed Aug. 29. 1966 Dec. 24, 1968 W. J. HASELOW ET AL SHEET INSPECTING AND SORTING APPARATUS Filed Aug. 29, 1966 9 Sheets-Sheet 7 Dec. 24, 1968 w. J. HASELOW ET AL 3,417,939

SHEET INSPECTING AND SORTING APPARATUS Filed Aug. 29, 1966 9 Sheets-Sheet 8 JZm/z iO/s United States Patent 0 SHEET lNSPECTlNG AND SORTING APPARATUS William J. Haselow, Kalamazoo, Mich., and William E.

Aschenbrenner, Wisconsin Rapids, Wis., assignors to Consolidated Paper, Iuc., Wisconsin Rapids, Wis., a

corporation of Wisconsin Filed Aug. 29, 1966, Ser. No. 575,704 15 Claims. (Cl. 27164) ABSTRACT OF THE DISCLOSURE Apparatus for automatically inspecting sheets of paper and separating acceptable and unacceptable sheets. The sheets are moved by a conveyor over a suction surface of variable effective width, past a scanning means. The sheets are diverted into selected paths by an endless flexible member which is mounted for pivotal movement and which cooperates with a guide roll to define the path to be followed.

Background of the invention In the manufacture of paper and other materials which are sold in the form of thin flexible sheets, the procedure utilized for quality control becomes of great importance, due to the extremely large number of individual sheets the quality of which must be controlled with substantial accuracy. Referring, by way of example, to the manufacture of paper in sheet form, it was once common to employ a large number of persons Whose job was to individually inspect the sheets after the stacking thereof. Eventually, various types of statistical sampling plans were proposed, and more recently highly successful apparatus has been developed for automatically removing representative sample sheets from each lot or load of paper so as to eliminate the necessity for inspection of the entire lot if inspection of the representative samples indicates satisfactory quality. For a complete description of automatic sheet sampling apparatus of the foregoing type, reference may be had to William J. Haselow US. Patents 3,180,190 and 3,205,741, both of which are assigned to the assignee of the present invention.

In order to further improve the accuracy and reduce the time and expense of quality control in the manufacture of paper and other thin flexible material in sheet form, various types of electronic inspection devices have been proposed for automatically inspecting an entire load of sheets or a selected representative sample therefrom. Such automatic inspection equipment eliminates the manual handling and visual inspection which would otherwise be required, and such equipment is believed capable of providing more reliable and consistent results in addition to effecting a great saving in time and a substantial reduction in the expense of maintaining quality control of sheeted paper and other material.

Despite the foregoing significant developments in the art of inspecting sheeted paper and the like, the sheet handling apparatus heretofore provided for use in conjunction with an automatic sheet inspection device has not permitted realization of the full benefits which such inspection equipment is believed to be capable of providing. For example, in order to automatically inspect a plurality of sheets of paper, such sheets must be conveyed past scanning means associated with the inspecting device, and the sheets should perferably be conveyed at relatively high speed and in spaced apart relation. Heretofore, no entirely satisfactory sheet conveying mechanism has been found which accomplishes the foregoing objectives and at the same time holds the sheets in such a manner as to maintain them in proper alignment and avoid any damage to the sheets. Moreover,

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difficulties have been encountered in holding the moving sheets during the time they are exposed to the scanning apparatus so as to maintain them in a substantially flat condition without wrinkles or other surface distortions. Relative to the last-mentioned problem, it will be understood that if the surface of the sheet is temporarily distorted or wrinkled in any way as it passes across the scan line of a photoelectric inspection device, the latter will sense spurious defects in the sheet. This is particularly true when defects are detected by measurement of reflected light differential, since temporary surface distortions will cause variations in the normal level of reflected light from acceptable quality sheets.

Another serious problem which has been encountered in the design of sheet-handling apparatus for use with automatic inspection equipment has been to provide sorting mechanism, operable for example by a memory system associated with the inspecting device, for separating the acceptable and unacceptable sheets at high production speeds and without damage to the sheets. Thus, many difficulties have been presented in attempts to divert a sheet moving at high speed from a main path to a secondary path without having jam-ups occur due to delays in the movement of a rejected sheet as the latter engages against a diverter gate or reject device or the like.

Another difliculty in the design of sheet-handling apparatus of the foregoing type has been to provide for the conveying of the sheets to respective accept and reject layboys after passing by a diversion gate or sorting device so as to produce a continuous flow or stream of overlapped sheets to each layboy even though the sheets are spaced apart as they leave the scanning area and subsequently follow a given one of two different paths depending upon the quality determination made by the automatic inspector.

Objects of the invention It is a general object of the present invention to provide sheet conveying and sorting apparatus which is designed for use in conjunction with an automatic sheet inspection device and which eliminates the foregoing difiiculties heretofore encountered in passing sheets at high speed past a scanning device and thereafter separating acceptable and unacceptable sheets into different stacks or the like.

A more specific object of the invention is to provide a sheet-conveying suction device capable of separating a supply of overlapped sheets and feeding such sheets at high production speeds past a scanning component of a sheet inspection device without significantly changing sheet alignment and without damage to the sheets.

A further object of the invention is to provide a sheetconveying suction device as last above-mentioned which is capable of holding each sheet so as to be free of temporary surface distortions as the sheet passes the scanning member thereby minimizing the possibility of spurious defects being detected in acceptable quality sheets.

An additional one of our objects is to provide an improved high speed diversion gate means for directing each of a plurality of inspected sheets along a given one of two paths depending upon whether a particular sheet has been determined by an associated inspecting device to be of acceptable or unacceptable quality.

Still another of our objects is to provide a diversion gate device as last above-mentioned including continuously moving diverter means for exerting a positive force on a sheet in order to divert the same from a primary path to a secondary path thereby permitting operation of the diversion gate device at unusually high speeds while minimizing the occurrence of sheet delay or retardation when a sheet engages against the diverter means.

A further object of the present invention is to provide improved overlap control means for controlling the conveying of sheets in overlapped condition to respective accept and reject layboys subsequent to the inspection of such sheets and the sorting thereof by the above-mentioned diversion gate device, such control means including sheet-sensing means for sensing the presence of a sheet at a given location along a conveyor path and controlling the starting and stopping of overlap conveyor means in accordance therewith.

The drawings FIGURES 1A, 1B and 1C, taken together in side-byside relation, comprise a side elevational view of automatic sheet inspecting and sorting apparatus including sheet conveying and sorting means constructed in accordance with the present invention;

FIGURE 2 is an enlarged fragmentary side elevational view showing a vacuum box and associated sheet conveyor for conveying a plurality of sheets one at a time in spaced relation pasta scanning component of an automatic inspection device;

FIGURE 3 is a further enlarged fragmentary vertical sectional view of the apparatus of FIGURE 2, certain rollers and-the like being removed to more clearly illustrate the vacuum box and the manner in which a sheet conveyor belt moves thereover;

FIGURE 4 is a transverse vertical sectional view, partly broken away, taken substantially along the line 4-4 of FIGURE 3;

FIGURE 5 is a schematic side elevational view illustrating a pivotally mounted diversion gate assembly comprising a pair of rolls at least one of which is driven having a plurality of endless tapes mounted thereon, the assembly being shown in solid lines in a normal position for directing an acceptable sheet along a primary path to an accept layboy or the like, and being shown in dotted lines in a reject position for directing a rejected sheet along a secondary path to a reject layboy or the like;

FIGURE 6 is an enlarged fragmentary side elevational view showing the diversion gate assembly of FIGURE 5 together with actuating means for pivotally moving the assembly between a normal accept position and a reject position;

FIGURE 7 is an elevational view looking approximately in the direction of the arrows 7-7 of FIGURE 6;

FIGURE 8 is a fragmentary horizontal sectional view taken substantially along the line 88 of 'FIGURE 6;

FIGURE 9 is a somewhat schematic view, taken substantially along the line 99 of FIGURE 1A, showing drive mechanism and associated clutch and brake means for intermittently driving slow speed overlap conveyor tapes which convey acceptable sheets in overlapped relation to an accept layboy;

FIGURE 10 is a somewhat schematic view, taken substantially along the line 10-10 of FIGURE 1B, showing drive mechanism and associated clutch and brake means for intermittently driving slow speed overlap conveyor tapes which convey rejected sheets in overlapped relation I Description of the inventiort In order to acquaint those skilled in the'art with the manner of making and using our invention, we have illustrated in the accompanying drawings and will now describe a preferred embodiment presently contemplated by us as the best mode of carrying out our invention.

Referring now to the drawings, and in particular to FIGURE 1C, there is shown sheet feeding apparatus 1,

conveyor means II which receives sheets from the feeding apparatus I and conveys the same in overlapped relation, an electronic sheet inspection device or the like III, and a vacuum pickup device IV which separates the overlapped sheets and conveys them one at a time in spaced relation past the inspector or scanner III. FIGURE 13 shows a diversion gate assembly V, a slow speed accept sheet overlap conveyor system V1, a slow speed reject sheet overlap conveyor system VII, and a reject or secondary layboy VIII. FIGURE 1A shows an accept or primary layboy IX.

It will be understood from the foregoing outline of the major components of the automatic sheet inspecting and sorting mechanism to be described herein that a stack of sheets to be inspected is supplied to the sheet feeding apparatus I, the sheets are delivered from the feeding apparatus I to the conveyor II which conveys the same in overlapped condition to the vacuum pickup device IV. The vacuum pickup device IV accelerates the sheets so as to space them from one another, and it conveys the sheets one at a time past the scanning or inspecting apparatus III which includes memory and printout equipment (not shown) for controlling the operation of the diversion gate assembly V. The diversion gate assembly or sorting device V directs acceptable sheets on to the accept overlap sheet conveyor section VI which effects overlapping of the sheets and feeds them in a continuous stream at a relatively low speed to the accept or primary layboy IX. In addition, the diversion gate assembly V directs reject sheets to the reject overlap conveyor section VII which effects overlapping of such sheets and feeds them in a continuous stream at a relatively low speed to the reject or secondary layboy VIII.

The sheet feeding apparatus I does not in itself form a part of the present invention and thus will be described only briefly herein. There is shown a platform 20 having a stack of sheets S to be inspected positioned thereon. Above the stack of sheets S there is provided a vacuum cup apparatus shown schematically at 22 which lifts the trailing end of the top sheet and feeds the same forwardly into a nip defined between a pair of feed rolls 24 and 2 6, and the platform 20 is slowly raised in a continuous manner as sheets are fed from the top of the stack so as to maintain a substantially constant distance between the vacuum cup apparatus 22 and the top of the stack of sheets S. The sheet feeding apparatus I delivers the sheets in partially overlapped relation to the feed rolls 24 and 26, at least one of which is driven, and the feed rolls conduct the sheets forwardly over a stationary plate 28 to the conveyor II.

The sheet conveyor II includes an upper fixed plate 30 and a lower sheet conveyor member compriing a plurality of laterally spaced tapes 32 which extend over a tape roll 34 at the left-hand end of the conveyor and over a tape roll 36 at the right-hand end thereof. The roll 36 is driven in a counterclockwise direction from a variable gear box 38 which in turn is driven from a motor 40 as will be described more fully hereinafter. The overlapped sheets S rest on the moving tapes 32 and are advanced thereby to the suction pickup device IV. It will be understood that the stationary plate 30 overlies the sheets on the conveyor tapes 32 and aids in controlling the sheets, while the moving tapes 32 perform the conveying function, However, in some applications it may be desired to substitute a plurality of upper driven tapes in place of the stationary plate 30.

The suction pickup conveyor device IV is best shown in FIGURES 2-4 and comprises an air porous endless belt 42 (See FIGURE 2) which extends over a steel spiral roll 44, an adjustable steel spiral tension roll 46, a steel spiral roll 48, a steel knurled fabric guide roll 50 which is pivotable about one end in a'manner known in the art to control the fabric 42, a steel spiral roll 52, a knurled steel drive roll 54, and a spread roll 56. A suction box 58 is disposed between the upper and lower reaches of the endless fabric belt 42 and is arranged so that the upper reach of the belt moves across the upper surface of a suction top plate 60. A small steel rider roll 61 is positioned at the top of the fabric 42 adjacent the left-hand end of the suction top plate so as to prevent air from flowing back under a sheet on the suction plate, particularly air from air blasts which may be used to control the sheets as they leave the fabric 42 and are delivered to the next conveyor. A rubber roll 62 is disposed outside of the fabric belt 42 adjacent the drive roll 54 so as to press the fabric against the latter, and the drive roll 54 is driven in a counterclockwise direction from a main drive pulley 64 (see FIGURE 1C) which in turn is driven from the motor 40 by means of a motor pulley 66 and a timing belt 68. Accordingly, the endless porous fabric belt 42 is driven in a counterclockwise direction as viewed in FIGURE 2, and adjustable means 70 is associated with the roll 46 for varying the position of the latter and thereby controlling the tension of the belt 42.

The action box 58 includes a suction or vacuum chamber 71 defined by the top plate 60, a pair of side walls 72 and 73, a pair of end walls 74 and 75, and a bottom plate 76. A vacuum header or pipe 78 is connected with the chamber 71 at openings 80 and 82 in the bottom plate 76, and a vacuum source (not shown) is associated with the header 78 in order to produce a vacuum within the chamber. In the particular embodiment described herein, sealing means is provided comprising a bellows assembly indicated generally at 84 (see FIGURE 4) and including a compressible bellows member 86 disposed between a pair of squeeze plates 88 and 90. The bellows member 86 extends the full length of the suction box 58 and when squeezed between the plates 88 and 98 produces a seal between the top plate 60 and bottom plate 76 so as to divide the interior of the suction box into a suction area and a non-suction area. The bellows assembly 84 is movable laterally on a pair of rod members 92 and 94 (see FIGURE 3) so as to permit adjustment of the effective width of the vacuum area in accordance with the width of the sheets being inspected. A screw member 96 is rotatable for providing lateral movement of the bellows assembly 84, and a shaft 98 having a threaded portion thereon is rotatable in order to control relative movement of the plates 88 and 9t) and thereby effect squeezing of the bellows 86. The foregoing description is simply to illustrate one example whereby, if desired, the interior of the suction box 58 may be divided by sealing means so as to vary the width of the effective vacuum section 71, and of course various other types of adjustable sealing means may be utilized within the scope of the present invention.

The top plate 60 of the suction box 58 is apertured so as to permit suction to be applied to the porous belt 42 and through the latter to a sheet of paper disposed on the top surface of the belt. In the particular embodiment being described, the top plate 60 comprises a /8 inch thick metal plate having a plurality of staggered inch diameter holes 100 so as to provide a surface which is approximately 4.8% open. As stated above, the fabric belt 42 is driven in a counterclockwise direction by the roll 54 which in turn is driven from the main drive pulley 64. The speed of the fabric belt 42 is greater than the speed of the tapes 32 of the preceding conveyor II so as to separate the overlapped sheets as they leave the latter conveyor. A rubber covered idler roll 102 (see FIGURE 2) is disposed immediately above the suction top plate 60 approximately at a location where the suction area begins. The roll 102 exerts a light pressure on the sheets and assists in controlling the magnitude of the gap which is produced between the sheets due to the higher speed of the belt 42 relative to the speed of the conveyor tapes 32 so that a substantially constant gap is provided.

It will be understood from the foregoing that as the overlapped sheets S leave the tapes 32 they are delivered to the top of the faster moving porous belt 42 and pass beneath the roll 102 whereby such sheets are spaced apart any desired amount, e.g., one to four inches, as they are moved over the top plate 60 of the suction box 58. The amount of the sheet gap may be varied within a wide range by adjusting the variable gear box 38 of FIGURE 10. That is, the main drive pulley 64 drives a shaft 104 having a smaller pulley 106 mounted thereon, and a gear box 108 is driven from the pulley 106 by an endless belt '110. The variable gear box 38 is driven from the gear box 108 by a longitudinal shaft 112, and all of the components to the right of the suction pickup device IV in FIGURE 1C are driven from the gear box 38. On the other hand, the drive roll 54 which drives the porous belt 42 is mounted on the same shaft 104 as the main drive pulley 64 which as previously described is driven directly from the motor 40 through the belt 68. Accordingly, the speed of the porous belt 42 is controlled directly by controlling the speed of the motor 40, and the relative speed of the sheet feeder I and the tapes 32 of the conveyor II is controlled by adjusting the variable gear box 38. For example, once the speed of the motor 40 is selected, then the sheet gap at the suction pickup device 1V may be increased by adjusting the gear box 38 so as to slow down the tapes 32 relative to the porous belt 42, and vice versa.

It will now be seen that the vacuum pickup device IV separates the overlapped sheets supplied to the endless porous belt 42 and conveys the sheets past the automatic sheet inspection device III. FIGURE 3 shows the scan line of the inspection device, and it will be noted that the suction top plate 60 has a slight crown or hump which is in the area of the scan line and is indicated at 60a. The purpose of the hump or crown 60a is to cause a sheet passing thereover to be pulled or stretched slightly thereby eliminating temporary wrinkles and avoiding rejection of acceptable quality sheets. The suction pickup device IV will move the sheets in spaced relation and at an accurately determined speed past the electronic scanning apparatus III while fully exposing the sheets to the scanner and without significantly changing sheet alignment or causing any damage to the shets. Due to the suction provided beneath the fabric 42, each sheet in turn is firmly held in a substantially flat condition so as to adhere to the fabric and move at the speed of the latter while being fully exposed to the scanner,

It should be understood that the manner in which a sheet is supported or held as it is moved past the scanner III is quite important because the most common type of scanning apparatus comprises a light source and photo electric means for sensing changes in light reflected from the sheet. Obviously, any temporary surface distortion in the sheet as the latter passes the scan line will produce changes in light reflection readings which do not in fact signify defects in the sheet. Moreover, the suction pickup device IV provides substantial advantages over a conventional two-roll nip arrangement which at high speeds will not maintain proper sheet alignment, and which will tend to damage the sheets as the latter are accelerated for sheet separation if the nip pressure is not constant across the she:t and if sheet alignment is not correct. The vacuum pickup device IV of the present invention effects sheet separation at high production speeds without affecting sheet alignment, and due to the adhesion caused by the vacuum it holds the sheets in a substantially flat condition without wrinkles or other temporary surface distortions during the inspection phase of the process.

When the sheets S leave the suction pickup device IV they pass between a plurality of upper tapes 114 and a plurality of lower tapes 1167 The upper tapes 114 are trained over a tape roll 118 at their right-hand end (see FIGURE 1C) and over a tape roll 120 at their left-hand end (see FIGURE 1B), and the latter roll is driven from a longitudinal drive shaft 121 so as to drive the upper tapes 114 in a clockwise direction. The lower tapes 116 7 are trained over a tape roll 122 at their right-hand end (see FIGURE 1C), and over rolls 124, 126, 128, 130 and 132 at their left-hand end (see FIGURE 1B), and the tape roll 128 is driven in a counterclockwise direction from the longitudinal drive shaft 121 in order to drive the lower tapes 116. Thus, as the spaced sheets S leave the belt 42 of the suction pickup device IV, they enter between the upper and lower tapes 114 and 116 and are conveyed thereby to the diversion gate mechanism V.

As shown schematically in FIGURE 5, the diversion gate mechanism V comprises a pivotally mounted assembly including a pair of rolls 134 and 136 having a plurality of spaced endless tapes 138 mounted thereover. As will be described more fully hereinafter, at least one of the tape rolls 134 and 136 is driven in a clockwise direction so as to move the tapes 138 approximately at the speed of the sheets S, and the assembly is pivotally movable between a normal position as shown in solid lines and a reject position as shown in dash lines. The diversion gate mechanism V is controlled by a memory unit (not shown) associated with the sheet inspection device III, so that when an acceptable quality sheet approaches, the assembly V is moved to its solid line position, and when a reject sheet approaches, the assembly is moved to its dash line position.

The idler guide roll 132 as shown in FIGURE is positioned immediately beneath the tapes 138 for cooperation therewith, and to the left of the roll 132 there are provided a horizontal fixed plate 142 and a downwardly inclined fixed plate 144. When an acceptable quality sheet arrives at the diversion gate mechansim V, the sheet passes between the tapes 138 and the guide roll 132 and is directed over the fixed plate 142 along a primary path to the conveying means VI which will be described later herein. On the other hand, when an unacceptable sheet arrives at the diversion gate mechanism V, the latter is pivoted to its dash line position and as the sheet passes between the tapes 138 and the guide roll 132 it is directed under the fixed plate 144 along a downwardly inclined secondary path to conveying means VII also to be described later herein. In this manner, the diversion gate -mechansim V functions under the control of the inspection equipment III to separate acceptable and unacceptable sheets.

Reference is now made to FIGURES 6-8 which illustrate the diversion gate mechanism V in greater detail. FIGURE 8 shows a first housing block 146 having a relatively thick portion 147 which houses a ball bearing assembly 148, and a relatively thin housing portion 149. A second housing block 150 similarly includes a relatively thick portion 152 which houses a ball bearing assembly 154, and a relative thin housing portion 156. A pair of bolts 158 and 160 serve to rigidly bolt together the two housing blocks 146 and 150 so as to form a unitary housing assembly wherein the two bearings 148 and 154 are laterally offset from one another. In addition, a first pivot shaft 162 is welded or otherwise secured to a plate 164 which in turn is rigidly connected to the first housing block 146 by a plurality of bolts or the like (not shown). In a similar manner, a second pivot shaft 166 is welded or otherwise secured to a plate 168 which in turn is rigidly connected to the second housing block 150 by a plurality of bolts or the like (not shown), the second pivot shaft 166 being disposed in coaxial relation to the first pivot shaft 162.

The two pivot shafts 162 and 166 are mounted in respective bearing support members 170 and 172 so that the assembly of the bearing blocks 146 and 150 together with the bearing members 148 and 154 is pivotable as a unit about the axis of the two pivot shafts. It will further be seen that one end of a shaft 134' which carries the tape roll 134 is rotatably supported in the bearing 148, while one end of a shaft 136' which carries the tape roll 136 is rotatably supported in the bearing 154. Referring now to FIGURE 7, it will be understood that the other ends of the shafts 134 and 136 are supported in a hous- 8 ing block assembly 146, substantially identical to the assembly 146, 158 described above, so as to be rotatably mounted in ball bearings or the like and yet pivotally movable as a unit about the axis of the Pivot shafts 162 and 166.

A link 174 is pivotally connected at its upper end to the thin portion 156 of the housing block 150 by means of a mounting plate 176 which is bolted or otherwise secured to the housing block and has a stud 178 welded thereto. The upper end of the link 174 is pivotally carried on the stud 178 and retained thereon by a bolt 180 (see FIGURE 8). In a similar fashion, a link 182 is pivotally connected at its upper end to the portion 149 of the housing block 146 by means of a mounting plate 184 which is rigidly connected to the housing block and has a stud 1S6 welded thereon. The lower ends of the links 174 and 182 are associated with air cylinders 188 and 190 respectively for moving the links between upper and lower positions in accordance with the desired positions of the tape rolls 134 and 136. A second pair of links 174 and 182 are pivotally connected with the oppositely disposed housing blocks 146' and 150' and are controlled by air cylinders 188 and 190 for actuating the opposite ends of the shafts 134 and 136'. FIGURE 7 further shows the guide roll 132 Which is mounted on a shaft 192 having its opposite ends journaled in fixed bearing supports 194 and 196.

It will be understood from the foregoing that the air cylinders 188, 190, 188 and 190' serve to pivotally move the diversion gate assembly V between the solid line and dash line positions of FIGURE 5. Thus, when a sheet passing the scanning unit III is found to be acceptable, the memory unit associated with the scanner controls the four air cylinders when the sheet approaches the diversion gate assembly so as to move the links 174 and 174' upwardly and move the links 182 and 182 downwardly thereby pivoting the diversion gate assembly to the accept position as shown in FIGURE 6 and also in solid lines in FIGURE 5. On the other hand, when the scanning unit III senses that a sheet is of unacceptable quality, the memory unit actuates the four air cylinders 188, 190, 188' and 190' as the sheet approaches the diversion gate assembly V so as to move the links 174 and 174' downwardly and move the links 182 and 182' upwardly thereby pivoting the diversion gate assembly to the reject position shown in dash lines in FIGURE 5.

FIGURE 7 shows a drive pulley 198 which is mounted on one end of the shaft 134 for driving the tape roll 134 in a clockwise direction as viewed in FIGURE 6. A gear box 206 (see FIGURE 1B) is driven from the gear box 108 through the longitudinal drive shaft 121, and a pulley and timing belt (not shown) are utilized to drive the pulley 198 from the gear box 200. The tape roll 134 is thus driven from the gear box 280 and thereby serves to drive the plurality of tapes 138 in a clockwise direction as viewed in FIGURE 5, the tapes 138 preferably being driven at a speed approximately equal to the speed of the sheets S as the latter approach the diversion gate assembly V. It is important to note that when a sheet is delivered to the diversion gate assembly V and passes between the tapes 138 and the guide roll 132, the sheet is not slowed down by any appreciable amount even when the diversion gate tape rolls 134 and 136 are in the reject position shown in dash lines in FIGURE 5, because the tapes 138 which contact the sheet and deflect the same along the diverted secondary path are moving at approximately the same speed as the sheet. The diversion means of the present invention thus offers substantial advantages over prior art diversion means where a sheet engages against a stationary diverting member, since an arrangement of the latter type will at times slow down the sheet an amount sufficient to cause interference with succeeding sheets and j am-ups in the sheet conveying mechanism.

Another important feature of the diversion gate mechanism of the present invention is that the gate assembly V is timed so that when a first sheet is being directed along one path, and a second oncoming sheet is to be directed along a different path, the gate assembly V is pivoted from one position to another before the trailing end of the first sheet has completely passed between the diversion tapes 138 and the guide roll 132. For example, assume that a first sheet is being directed along the primary accept path above the plate 142, and that a second following sheet has been found unacceptable and is to be directed along the reject path beneath the plate 144. In accordance with the present invention, the gate assembly V will under such circumstances be pivoted from the solid line position of FIGURE to the dash line position therein while some portion of the trailing end of the first sheet, e.g., four to six inches thereof, has yet to pass between the diversion tapes 138 and guide roll 132. The latter procedure provides significant advantages over a diversion member which is or must be operated only at the gap between successive sheets, and in the present instance such a procedure is rendered entirely feasible due in large part to the fact that the diversion tapes 138 move at approximately the same speed as the sheets.

It should further be noted that the two diversion tape rolls 134 and 136 are pivoted about the axis of the shafts 162 and 166 which is located approximately midway between the two rolls, and the pivot axis is located substantially immediately above the corner or point of intersection between the horizontal or primary sheet path and the diverted or secondary downwardly inclined sheet path. The purpose of the latter arrangement is so that when the diversion gate mechanism is in its normal accept position as shown in solid lines in FIGURE 5, the tapes 138 will be parallel to the sheet path and will contact the guide roll 132 as a tangent thereto, and when the mechanism is pivoted to the reject position shown in dash lines in FIGURE 5 the tapes 138 will be parallel to the downwardly inclined secondary sheet path and will again contact the guide roll 132 as a tangent thereto. In other words, the pivot axis of the gate mechanism is located so that in either of the two positions of the rolls 134 and 136 the diversion tapes 138 are tangent to the cooperating guide roll 132.

The foregoing arrangement is important because it is extremely difficult to maintain perfect alignment between the plurality of spaced tapes 138 on the rolls 134 and 136 and the plurality of spaced tapes 116 which extend over the roll 132, and if there is wrapping of the tapes 138 on the tapes 116 then any misalignment between the two sets of tapes will cause the misaligned tapes 138 to hang over the edges of corresponding tapes 116 thereby producing longitudinal creases in the sheets S passing therebetween. The latter problem is completely obviated by mounting the pivotal assembly of the rolls 134 and 136 in the manner described, and with the arrangement of the present invention the diversion gate mechanism V can operate effectively at unusually high speeds without the occurrence of jam-ups, and the moving diversion tapes 138 when in the reject position exert a positive downward force on the sheet so that a sheet determined to be of unsatisfactory quality is actually pulled down the secondary sheet path, and the sheets engage the diversion tapes 138 at a point approximately immediately beneath the pivot axis of the diversion rolls. It should be understood that the particular links such as shown at 174 and 182, and the associated air cylinders 188 and 190, are described herein merely by way of example, and various other types of actuating means may be utilized within the scope of the present invention for pivoting the gate assembly between its accept and reject positions. For example, the four air cylinders 188, 190, 188' and 190' may be replaced with four single acting solenoids, or by two double acting air cylinders or solenoids.

FIGURE 1B shows a pair of tape rolls 204 and 206 which carry a plurality of spaced endless tapes 208, and beneath the latter there are provided a plurality of spaced tapes 210 which are trained over a pair of tape rolls 212 and 214. When an acceptable sheet S passes the diversion gate assembly V it is delivered between the lower reach of the tapes 208 and the upper reach of the tapes 210.

10 The tape roll 204 is driven in a clockwise direction in any suitable manner from the drive shaft 121, and the roll 212 is similarly driven in a counterclockwise direction, so as to convey the acceptable sheets to the left as viewed in FIGURE 1B and deliver the same between a further plurality of upper tapes 216 and lower tapes 218, the latter tapes comprising the primary overlap conveyor section VI. The upper tapes 216 are trained over a pair of tape trolls 220 and 222, and the latter roll is driven in a clockwise direction. The lower tapes 218 are trained at their extreme right-hand end over a tape roll 224 (see FIGURE 1B) and at their extreme left-hand end over a tape roll 226 (see FIGURE 1A), and intermediate guide rolls or idler rolls or the like 228, 230, 232 and 234 are also provided. The tape roll 226 is driven in a counterclockwise direction from a variable gear box 242 (see FIGURE 1B) in order to drive the lower tapes 218, as will be described more fully hereinbelow. It will be seen that the lower tapes 218 extend to the left far beyond the upper tapes 216, and thus above the tapes 218 at the left-hand end thereof there are provided a plurality of upper tapes 236 which are trained over a pair of tape rolls 238 (see FIGURE 1B) and 240 (see FIGURE 1A), the latter being driven in a clockwise direction from the gear box 242, as will also be described more fully hereinafter.

It will be generally understood from the foregoing that an acceptable sheet S, after passing the diversion gate mechanism V, first passes between the upper tapes 208 and the lower tapes 210, then passes between the upper tapes 216 and the lower tapes 218, and thereafter between the upper tapes 236 and the lower tapes 218. When a sheet leaves the tapes 218 it passes between a pair of side jogger plates such as shown at 244 (see FIGURE 1A) and engages against an end stop 246, the sheets being collected on an elevator-type platform 248. However, the sheets are spaced from one another and moving at relatively high speed prior to the time they reach the conveyor tapes 218, and when they reach the latter tapes they are slowed down and again overlapped before being delivered against the stop 246 of the primary layboy IX. The slowing down of the sheets is desirable to avoid damage and loss of control when the sheets engage against the stop 246. Moreover, various types of air blast means are often used to assist in floating the sheets onto the elevator platform 248, and it has been found that better control over the sheets is obtained when they are delivered to the layboy D( as a continuous stream of overlapped sheets. It will be understood, however, that in providing for the overlapping of the sheets when they arrive at the conveyor tapes 218, account must be taken of any gaps in the accept sheet supply caused by the diversion to a secondary path of any sheets found to be of unacceptable quality.

The apparatus for controlling the conveyor tapes 218 and 236 of the primary overlap conveyor section VI in order to provide for overlapping of the acceptable sheets being delivered to the primary layboy IX will now be described. As best shown in FIGURE 9, the variable gear box 242 acts through a drive shaft 250 to drive a gear box 252, and the latter acts through a pair of pulleys 254 and 256 and a belt 258 to supply driving torque to an electrically controlled clutch and brake assembly 260. When the clutch 260 is operatively engaged it drives a shaft 262 which in turn acts through gears 264 and 266 so as to rotate a shaft 268 on which the tape roll 226 is mounted, whereby the roll 226 is driven in a counterclockwise direction as viewed in FIG- URE 1A to drive the conveyor tapes 218. The end of the shaft 262 also carries a pulley 270 which acts through a belt 272 and pulley 274 to drive a shaft 276 on which the tape roll 240 is mounted. In this manner the roll 240 is driven in a clockwise direction as viewed in FIGURE 1A to drive the conveyor tapes 236. A segmented fibre guide roll 278 is also driven from the shaft 262 through a pair of pulleys 280 and 282 and a belt 284 so as to rotate the guide roll in a clockwise direction as viewed in FIGURE 1A. The conveyor tapes 218 and 236 are thus both driven from the variable gearbox 242, and the latter is regulated so as to drive the tapes at a slower speed than the preceding conveyor tapes 114, 116, 208, 210 and 216. Moreover, it will now be understood that both of the tapes 218 and 236 of the primary overlap conveyor section VI are driven through the normally engaged clutch assembly 260 so that disengagement of the latter will cause the two sets of tapes 218 and 236 to stop, while the above-mentioned tapes 114, 116, 208, 210 and 216 continue to be driven at a relatively high speed.

In order to control the clutch and brake assembly 260, there are provided a pair of sheet-sensing members 286 and 288 each of which may comprise a light source and associated light receiver or photocell. The sheetsensing members 286 and 288 are disposed in the secondary sheet path (see FIGURE 1B) and are spaced apart a' distance greater than the normal gap between consecutive sheets as they pass the gate diversion mechanism V. As shown in FIGURE 11, the photocells 286 and 288 are connected by leads 290 and 292 to a photoelectric relay 294, and the latter is connected through leads 296 and 298 to a control member 300 having a clutch coil 302 for controlling the operation of the clutch and brake assembly 260. Thus, whenever a rejected sheet is diverted by the gate mechanism V so as to pass along the secondary sheet path and interrupt the light beams associated with the photocells 286 and 288, a contact of the relay 294 is opened so as to deenergize the clutch coil 302 and thereby disengage the clutch and engage the brake of the clutch and brake assembly 260. In this manner, the conveyor tapes 218 and 236 of the primary overlap conveyor section VI are stopped whenever a rejected sheet interrupts either of the two light beams associated with the photocells 286 and 288, and such tapes remain stopped until both of the light beams are-uninterrupted. If two consecutive sheets are rejected, thesecond rejected sheet will interrupt the light beam to the photocell 286 before the first rejected sheet clears the photocell 288, and thus unnecessary stopping and starting of the conveyor tapes 218 and 236 is avoided under such circumstances.

It'Will now be understood that as long as acceptable sheets in spaced relation to one another are being continually supplied to the conveyor tapes 218 without any sheets'being diverted, the tapes 218 and 236 will continue to be driven through the normally engaged clutch 260; The sheets will thus become overlapped with respect to ane another due to the relatively slow speed of the tapes 218 and 236, so that the latter sets of tapes will deliver the acceptable sheets to the accept layboy IX in a continuous stream of overlapped sheets. However, whenever a sheet is rejected and thus diverted from the primary sheet path, the diverted sheet actuates the photocells 286 and 288 causing the tapes 218 and 236 to stop with the last accepted sheet disposed with its trailing end adjacent the extreme right hand end of the tapes 218, and the tapes 218 and 236 remain stopped until the light beams associated with both of the photocells 286 and 288 are cleared, by which time the next accept sheet will have reached an overlapped position with respect to the sheet waiting on the tapes 218 and the tapes 218 and 236 will again be operated.

Referring again to FIGURE 1B, a plurality of reject conveyor tapes 304 are trained over a tape roll 306 at their extreme right-hand end and over a tape roll 308 at their extreme left-hand end, with intermediate guide rolls or idler rolls or the like being provided at 310, 312 and 314. The tape roll 308 is driven in a clockwise direction in any suitable manner from a horizontal drive shaft 316 so as to drive the tapes 304, and as previously explained the tape roll 128 is driven in a counterclockwise direction so as to drive the tapes 116. When a rejected sheet leaves the tapes 116 it passes over a very short conveyor section 318 and then on to a plurality of tapes 320, the latter tapes comprising the secondary overlap conveyor section VII. The tapes 320 are trained at their extreme right-hand end over a tape roll 322 and at their extreme left-hand end over a tape roll 324, and guide or idler rolls or the like are also provided at 326 and 328. The tape roll 324 is driven in a counterclockwise direction from the variable gear box 242, in a manner to be described more fully hereinafter, so as to drive the reject overlap conveyor tapes 320.

It will be generally understood from the foregoing that a reject sheet S causes the diversion gate mechanism V to be positioned as shown in dash lines in FIGURE 5, whereby when the sheet engages the diversion tapes 138 it is pulled or diverted along a downwardly inclined path beneath the stationary plate 144 so as to pass between the conveyor tapes 116 and 304. A rejected sheet next passes over the short conveyor section 318 and then between the tapes 304 and 320. There is also provided a very short conveyor section above the conveyor tapes 320 and at the left-hand end of the tapes 304, such short section comprising a plurality of tapes 329 mounted on tape rolls 331 and 333, the roll 333 being driven in a clockwise direction. When the rejected sheet leaves the lefthand end of the tapes 320 it is delivered to the reject layboy VIII, the sheets being fed between side guide plates 330 and against a stop plate 332, and finally being collected on an elevator-type platform 334. The rejected sheets are moving at a relatively high speed prior to the time they reach the conveyor tapes 320, and when they reach the latter tapes they are slowed down and overlapped before being delivered against the stop 332 of the reject or secondary layboy VIII. It will be understood that whenever sheets are found to be acceptable and are delivered along the primary path by the diversion mechanism V, then corresponding spaces result between the sheets being rejected, and thus in order to provide for overlapping of the rejected sheets, the conveyor tapes 320 are stopped when an acceptable sheet is sensed, so as to Wait for the next reject sheet, as will be explained more fully hereinbelow.

The apparatus for controlling the conveyor tapes 320 and 329 of theisecondary overlap conveyor section VII in order to provide for overlapping of the rejected sheets being delivered to the secondary layboy VIII will now be described. Referring to FIGURE 10, the variable gear box 242 drives a gear box 336 which acts through a pair of pulleys 338 and 340 and a belt 342 to rotate a shaft 344. The shaft 344 acts through an electrically controlled clutch and brake assembly 346 to drive a shaft 348 on which a segmented guide roll 350 is mounted, the guide roll being rotated in a clockwise direction as viewed in FIGURE 1B. The shaft 348 acts through a pair of gears 352 and 354 to drive the tape roll 324 in a counterclockwise direction as viewed in FIGURE 1B. In addition, the shaft 348 acts through a pair of pulleys 356 and 358 and a belt 360 to drive the tape roll 333 in a clockwise direction for the purpose of driving the short upper conveyor tapes 329. The conveyor tapes 320 and 329 are thus both driven from the variable gear box 242, and the latter is regulated so as to drive the tapes 320 and 329 at a slower speed than the preceding tapes 116 and 304. It will also now be understood that the tapes 320 and 329 are both driven through the normally engaged clutch assembly 346 so that disengagement of the latter will cause the two sets of tapes 320 and 329 to stop, while the above-mentioned tapes 116 and 304 continue to be driven at a relatively high speed.

In order to control the clutch and brake assembly 346, there are provided a pair of sheet-sensing members 362 and 364 each of which may comprise a light source and associated photocell. The sheet-sensing members 362 and 364 are disposed at the primary sheet path as shown schematically in FIGURE 1B and are spaced apart a distance greater than the normal gap between consecutive sheets as they pass the gate diversion mechanism V. As shown in FIGURE 11, the photocells 362 and 364 are connected by leads 366 and 368 to a photoelectric relay 370, and the latter is connected through leads 372 and 374 to a control member 376 having a clutch coil 378 for controlling the operation of the clutch and brake assembly 346. Thus, whenever an acceptable sheet passes the gate diversion mechanism V and moves along the primary sheet path so as to interrupt the light beams associated with the photocells 362 and 364, a contact of the relay 370 is opened so as to deenergize the clutch coil 378 and thereby disengage the clutch and engage the brake of the clutch and brake assembly 346. In this manner, the conveyor tapes 320 and 329 are stopped whenever an acceptable sheet interrupts either of the two light beams associated with the photocells 362 and 364, and such tapes remain stopped until both of the light beams are again uninterrupted. If two consecutive sheets are accepted, the second accepted sheet will interrupt the light beam to the photocell 364 before the first accepted sheet clears the photocell 362, and thus unnecessary stopping and starting of the conveyor tapes 320 and 329 is avoided under such circumstances.

It will now be understood that whenever a plurality of consecutive sheets are being rejected, the tapes 320 and 329 will continue to operate, and the sheets will become overlapped with respect to one another due to the relatively slow speed of the tapes 320 and 329 so that the latter sets of tapes will deliver the rejected sheets to the reject or secondary layboy VIII in a continuous stream of overlapped sheets. Whenever a sheet is accepted and moves along the primary sheet path it actuates the photocells 362 and 364 causing the tapes 320 and 329 to stop with the last rejected sheet disposed with its trailing end adjacent the extreme right-hand end of the tapes 320, and the tapes 320 and 329 remain stopped until the light beams associated with both of the photocells 362 and 364 are cleared, by which time the next rejected sheet will have reached an overlapped position with respect to the sheet waiting on the tapes 320, and the tapes 320 and 329 will again be operated.

FIGURE 1B further shows a sheet-sensing member 380 disposed in the primary sheet path, and a sheet-sensing member 382 disposed in the secondary sheet path, for the purpose of counting the accept and reject sheets, respectively. Each of the foregoing sheetsensing members may comprise a photocell and associated light beam which is interrupted by the presence of a sheet. Referring to FIG- URE 11, the photocell 380 is connected by leads 384 and 386 to a photoelectric relay 388 which in turn is connected to a sheet counter mechanism 390 through leads 392 and 394. The contact of the relay 388 is arranged to close each time the light to the photocell 380 is broken, thereby providing a count of the acceptable sheets. In a similar manner, the photocell 382 is connected by leads 396 and 398 to a photoelectric relay 400 which in turn is connected to a sheet counter mechanism 402 through leads 404 and 406. The contact of the relay 400 is arranged to close each time the light to the photocell 382 is broken, thereby providing a count of the rejected sheets.

It will be seen from the foregoing description that the sheetsensing members 286 and 288 which control the operation of the tapes 218 and 236 of the primary overlap conveyor section VI are disposed in the path of the reject sheets, and in effect such sensing members sense the presence of an accept sheet by sensing the absence of a rejected sheet. Similarly, the sheet-sensing members 362 and 364 which control the operation of'the tapes 320 and 329 of the secondary overlap conveyor section VII are disposed in the path of the accept sheets and in eifect sense the presence of a rejected sheet by sensing the absence of an accept sheet. One important advantage of such an arrangement is that when the load of sheets to be inspected is exhausted and thus none of the light beams is interrupted, the accept conveyor tapes 218 and 236 and the reject conveyor tapes 320 and 329 will all run continuously so that all sheets will be cleared from the machine and delivered to the respective reject and accept layboys VIII and IX.

It will be understood however that alternative overlap control arrangements may be utilized. For example, the sheet-sensing members 362 and 364 may be eliminated and as a substitute therefor a single sheet-sensing member may be disposed along the secondary path in the area of the sensing members 286 and 288 but in this instance arranged so as to close the contact of the relay 370 and energize the clutch coil 378 thereby engaging the clutch 346 Whenever the sensing member senses the presence of a reject sheet along the secondary sheet path. It will be understood that if the sensing means for controlling the accept conveyors are in the accept or primary path while the sensing means for controlling the reject conveyors are in the secondary or reject path, then in each instance the presence of a sheet must cause the corresponding tapes to be driven. Consequently, when the supply of sheets to the mechanism is exhausted, those sheets still in the machine will not automatically be delivered to the respective layboys to clear the machine. It will further be understood that when sensing members are used singly rather than in pairs, the gap between the sheets will cause stopping and starting of the overlap conveyor tapes even when a plurality of consecutive sheets are being directed along the same path.

The apparatus of the present invention when used in conjunction with electronic sheet inspection mechanism or the like is highly advantageous as a means for inspecting and sorting sheeted paper or other flexible material in sheet form. Because of the design of the suction pickup mechanism IV and the gate diversion mechanism V it is possible to operate the apparatus at unusually high speeds and with increased accuracy. Various inspection techniques may be used in conjunction with the present invention for the inspection of sheeted material. One recommended procedure is to utilize sheet sampling apparatus to select a predetermined number of representative sample sheets from a total load and then to run the sample sheets through the inspection and sorting apparatus. When the accept and reject counters indicate more than a predetermined percentage of reject sheets in a sample, then the entire load from which the sample was taken may be run through the inspection and sorting apparatus. Otherwise, the load may be passed without further inspection. The sheets to be inspected are initially delivered by the feeder I in overlapped condition, the sheets are spaced apart by the suction pickup device IV to permit scanning by the inspection device III, and atfer being sorted by the gate diversion mechanism V both the accept sheets and the reject sheets are slowed down and again overlapped by the conveyor sections VI and VII, respectively, so as to be delivered as two continuous streams of overlapped sheets to the accept layboy IX and the reject layboy VIII.

It is important to observe that in accordance with the sheet sorting apparatus of the present invention, each and every sheet is at all times under positive physical control, ie., firmly held or pressed against conveying means therefor, from the sheet feeder I to the layboys VIII and IX, whereby sheets cannot become misaligned, misspaced or fly through space so as to cause jamming of the apparatus or damage to the sheets. It is this continuous control over the sheets which results in the capability of such sorting apparatus for extremely highspeed operation, e.g., up to 2000 feet per minute.

While we have described our invention in certain preferred forms, we do not intend to be limited to such forms, except insofar as the appended claims are so limited, since modifications coming within the scope of our invention will readily occur to those skilled in the art, particularly with our disclosure before them.

We claim:

1. For use in conjunction with sheet inspection apparatus of a type including scanning means which automatically inspects the quality of sheets of paper or the like, the improvement comprising sheet conveying means for supporting and transporting sheets past said scanning means to permit inspection of the sheets, said sheet conveying means including, in combination, suction means having a suction surface facing said scanning means, and conveying means movable over said suction surface in contact therewith, said conveying means being air porous so that said suction means will act through said conveying means causing sheets to adhere to said conveying means for conjoint movement therewith while being exposed to said scanning means for inspection and said suction surface being provided with a hump portion immediately opposite said scanning means whereby the portion of a sheet being scanned will in effect be wrapped on said hump portion so as to minimize the formation of temporary surface distortions during the scanning of the sheet.

2. For use in conjunction with sheet inspection apparatus of a type including scanning means which automatically inspects the quality of sheets of paper or the like, the improvement comprising sheet conveying means for supporting and transporting sheets past said scanning means to permit inspection of the sheets, said sheet conveying means including, in combination, suction means having a suction surface facing said scanning means, conveying means movable over said suction surface in contact therewith, said conveying means being air porous so that said suction means will act through said conveying means causing sheets to adhere to said conveying means for conjoint movement therewith while being exposed to said scanning means for inspection, said suction means including a suction box the top of which comprises said suction surface, and sealing divider means disposed within said suction box and arranged longitudinally therein, said divider means being adjustable laterally for varying the effective width of said suction box.

3. For use in conjunction with sheet inspection apparatus of a type including scanning means which automatically inspects the quality of sheets of paper or the like, the improvement comprising sheet conveying means for supporting and transporting sheets past said scanning means to permit inspection of the sheets, said sheet conveying means including, in combination, suction means having a substantially flat generally horizontal stationary suction surface disposed beneath said scanning means so as to face the latter, conveying means including an endless flexible member which is trained over said suction surface and is movable over said suction surface in contact therewith at a predetermined speed, supply means for supplying sheets in overlapped relation to the top of said endless flexible member so as to be carried by the latter over said suction surface and past said scanning means, said endless flexible member being air porous so that said suction means will act therethrough causing said sheets to adhere to said flexible member for conjoint movement therewith While being exposed to said scanning means for inspection, and'said flexible member being driven at a speed greater than the speed of said supply means so as to space said sheets from one another before transporting the same past said scanning means, and a pressure roller disposed above said suction surface in contact with the top of said flexible member, said roller being transverse to the path of said sheets and located approximately at the beginning of the effective portion of said suction surface so that sheets being carried by said flexible member will pass beneath said pressure roller approximately at the time they enter over the eflective portion of said suction surface thereby to assist in controlling the spacing of said sheets.

4. For use in conjunction with apparatus for handling sheets of paper or other flexible materials including sheet diversion mechanism for directing each sheet supplied thereto along a selected one of at least two different paths, the improvement comprising, in combination, a first overlap conveyor section arranged in a first sheet path for receiving sheets supplied thereto and delivering the same in overlapped relation to a first storage means, a second overlap conveyor section arranged in a second sheet path for receiving sheets supplied thereto and delivering the same in overlapped relation to a second storage means, first drive means including first clutch means for driving said first overlap conveyor section, second drive .means including second clutch means for driving said second overlap conveyor section, and sheet sensing means disposed along at least one of said first and second sheet paths so as to sense as to each sheet delivered from said sheet diversion mechanism whether the sheet is being delivered along said first path or said second path, said sheet sensing means being associated with said first and second clutch means for controlling the engagement and disengagement thereof so that when a sheet is conveyed along said first path by said diversion mechanism said first clutch means will be engaged and said second clutch means will ,be disengaged and when a sheet is conveyed along said second path by said diversion mechanism said first clutch means will be disengaged and said second clutch means will be engaged whereby whenever a sheet is directed along one of the paths then the overlap conveyor section associated with the other of the paths will be stopped until a further sheet is directed along said other path, the timing of said sheet sensing means being regulated so that wheneverone of the overlap conveyor sections is stopped with sheet waiting thereon such conveyor section will be started again only after a further sheet has been directed along its corresponding path and reached an overlap condition relative to said waiting sheet.

5. The invention'of claim 4 where said first and second clutch means are electrically .actuated and where said sheet sensing means comprises a plurality of light sources and corresponding light receiving photocell means 6. The invention of claim 5 where said sheet sensing means comprises first photocell means for controlling said first clutch means and second photocell means for controlling said second clutch means, and where at least one of said first and second photocell means comprises a pair of photocells and corresponding light sources disposed along one of said paths and spaced apart a distance greater than the normal gap between successive sheets delivered from said diversion means, said pair of photocells being interconnected so that when light to said photocells is interrupted so as to impose a condition upon a corresponding clutch means, said clutch means will re main so conditioned until both of the light sources associated with the photocells in said pair are uninterrupted thereby preventing stopping and starting of the corresponding overlap conveyor section as would otherwise be caused due to the normal gap between successive sheets delivered thereto.

7. The invention of claim 5 where said first electrically actuated clutch means is normally engaged to drive said first overlap conveyor section, and where the sheet sensing means for controlling said first clutch means comprises at least one photocell means disposed along said second sheet path for disengaging said first clutch means upon sensing the presence of a sheet moving along said second sheet path.

8. The invention of claim 5 where said first electrically actuated clutch means is normally engaged to drive said first overlap conveyor section and said second electrically actuated clutch means is normally engaged to drive said second overlap conveyor section, the sheet sensing means for controlling said first clutch means comprising at least one photocell means disposed along said second sheet path for disengaging said first clutch means upon sensing the presence of a sheet moving along said second sheet path, and the sheet sensing means for controlling said second clutch means comprising at least one photocell means disposed along said first sheet path for disengaging said second clutch means upon sensing the presence of a sheet moving along said first sheet path.

9. For use in conjunction with sheet handling apparatus for delivering sheets of paper or other flexible material selectively along at least two paths, the improvement comprising sheet diversion mechanism including, in combination, diversion gate means including a pair of rolls having at least one endless flexible member trained thereover, said diversion gate means being mounted for pivotal movement about a pivot axis intermediate the axes of said pair of rolls and being intermittently pivotally movable between a first position wherein a sheet engaging portion of said endless flexible member is generally aligned with a first path for directing a sheet therealong and a second position wherein said sheet engaging portion is generally aligned with a second path for directing a sheet therealong, guide roll means rotatably mounted immediately adjacent the sheet engaging portion of said endless flexible member so that each sheet supplied to said diversion gate means will pass between said endless flexible member and said guide roll means, actuating means for pivoting said diversion gate means into a selected one of said two positions so as to render the same capable of directing each sheet supplied thereto along a selected one of said two paths, and drive means for continuously driving said endless flexible ,member so that said sheet engaging portion thereof moves in the approximate direction of a given one of said two paths in accordance with the pivotal position of said diversion gate means whereby when one of said sheets engages said endless flexible member it is positively pulled thereby along a selected one of said two paths.

10. The invention of claim 9 wherein said diversion gate means is pivotally movable about a pivot axis located approximately midway between the axes of said pair of rolls.

11. The invention of claim 9 where said rotatable guide roll means is mounted on a stationary axis for cooperation with the sheet engaging portion of said endless flexible member in each of the two positions of said diversion gate means.

12. The invention of claim 9 where said diversion gate means is pivotally movable about a pivot axis located approximately midway between the axes of said pair of rolls, and said rotatable guide roll means is mounted on a stationary axis for cooperation with the sheet engaging portion of said endless flexible member in each of the two positions of said diversion gate means.

13. For use in conjunction with sheet handling apparatus for delivering sheets of paper or other flexible material selectively along at least two paths, the improvement comprising sheet diversion mechanism including, in combination, diversion gate means including a pair of rolls having at least one endless flexible member trained thereover, said diversion gate means being mounted for pivotal movement about a pivot axis intermediate the axes of said pair of rolls and being intermittently pivotally movable between a first position wherein a sheet engaging portion of said endless flexible member is generally aligned with a first path for directing a sheet therealong and a second position wherein said sheet engaging portion is generally aligned with a second path for directing a sheet therealong, guide roll means rotatably mounted immediately adjacent the sheet engaging portion of said endless flexible member so that each sheet supplied to said diversion gate means will pass between said endless flexible member and said guide roll means, actuating means for pivoting said diversion gate means into a selected one of said two positions so as to render the same capable of directing each sheet supplied thereto along a selected one of said two paths, and drive means for continuously driving said endless flexible member so that said sheet engaging portion thereof moves in the approximate direction of a given one of said two paths in accordance with the pivotal position of said diversion gate means whereby when one of said sheets engages said endless flexible member it is positively pulled thereby along a selected one of said two paths, said rotatable guide roll means being mounted on a stationary axis located so that said guide roll means will engage said endless flexible member approximately along a line where said two sheet paths intersect one another whereby said sheet engaging portion of said endless flexible member will be approximately tangent to said guide roll means in each of the two pivotal positions of said diversion gate means.

14. The invention of claim 13 where said diversion gate means is pivotally movable about a pivot axis located approximately midway between the axes of said pair of rolls.

15. The invention of claim 14 where said endless flexible member comprises a first plurality of spaced endless tapes trained over said pair of rolls, said guide roll means being mounted immediately adjacent to the sheet engaging portion of said first plurality of tapes, and a second plurality of endless tapes trained over said guide roll means for cooperation with said first plurality of tapes.

References Cited UNITED STATES PATENTS 1,545,910 7/1925 Maxson 271-76 2,795,312 6/1957 Howdle 271-64 X 3,008,576 11/1961 Hanson 271-64X 3,198,517 8/1965 Martin 271-74 3,321,121 5/1967 Nyberg 271-74 X M. HENSON WOOD, JR., Primary Examiner. R. A. SCHACHER, Assistant Examiner.

U.S. Cl. X.R. 

